The name hasn’t changed for almost half a century, but the Porsche 911 has evolved massively, from a peaky race car for the road that was likely to bite you, to a docile, usable supercar that’s as easy to drive as a Toyota – only far more exciting. When it comes to motoring greats, no car is more iconic than the mighty 911.

If you do decide to take the plunge, it’s essential that you inspect lots of examples first and you buy from a reputable source. Asking prices are all over the place, while specification, history and condition make a huge difference to values. As a rule of thumb, the impact-bumper cars are worth the least, and of the earlier models, it’s the T that’s the least valuable.

The most valuable is the S, which leaves the E in the middle. A Sportomatic gearbox chips 20 per cent off the value while Targas are also worth around 10 per cent less than an equivalent coupé. Cabriolets are worth 10-15 per cent more than an equivalent coupé.

You’ll need at least £7000 to buy a project 911SC or neglected early car, but you’ll need a lot of time, patience and expertise to revive it. You’re better off finding at least £13,000 for a reasonable T or SC, but if you want something tasty you’ll be doing well to spend less than £25,000 on a good Carrera 2.7 – which is the price of a really superb Turbo.

If money really isn’t an issue, you could try finding an RS 2.7, but depending on which model you want, a running car will cost upwards of £50,000 – and possibly three times that for an exceptional Lightweight.